The present invention relates to a device and to a method for producing packages of stacked materials, especially in the form of blocks comprising a plurality of individual signatures.
A device for stacking signatures is described in, for example, DE 697 12 364 T4. The signatures are first moved by a conveying unit along a substantially arc-shaped signature path from a horizontal position to a vertical position and stacked on a stacking table. Above the stacking table, the signature path comprises a vertical end section, so that the signatures are stacked with a substantially vertical orientation on the stacking table. By arranging signatures next to each other in a row, so-called “blocks” are formed, which are strapped to compress them and then packaged.
A similar device which stacks signatures to form a block is disclosed in DE 600 04 631 T2.
These devices usually operate with a conveying device which transports the stream of signatures in fish-scale fashion, that is, with an edge area of one signature resting on an edge area of the adjacent signature, to the stacking table. The problem here is that, when freshly printed signatures are fish-scaled for transport, printing ink can be transferred from one signature to another.
For this reason, it would be preferable in these areas of application to feed the sheets separately, i.e., to transport the signatures singly, one by one. In the area where the signatures are stacked, however, problems can be expected when the incoming signatures impinge on the signatures already stacked, because each newly arriving signature no longer receives the guidance achieved by the fish-scaling, which is no longer operative.